JP4537902B2 - Horizontal automatic welding equipment - Google Patents

Description

  The present invention mainly supports a workpiece made of a metal plate such as stainless steel, iron, or electrogalvanized steel plate bent into a cylindrical shape, a tapered shape, or a rectangular tube shape with a horizontal mandrel, and both ends of the workpiece are supported by a mandrel. It is related to the improvement of horizontal automatic welding equipment that produces various products such as drums, round pipes, tapered pipes and square pipes by butt welding on the back bar provided on the upper surface side. The present invention relates to a horizontal type automatic welding apparatus that can be accurately butted on a back bar of a mandrel without shifting in a direction.

  Conventionally, as this type of horizontal automatic welding apparatus, for example, an automatic welding apparatus for a thin metal sheet previously developed by the applicant of the present application is known (for example, see Patent Document 1).

  That is, although not shown, the automatic welding apparatus is supported in a cantilever state on the frame body, and is a long mandrel with a horizontal posture that supports a workpiece bent into a cylindrical shape, a tapered shape, or a rectangular tube shape. A long back bar that is detachably attached to the upper surface side of the mandrel, and a center positioning mechanism that is provided on the mandrel and positions the end surface of the work so that both ends of the work are abutted on the back bar, A clamp mechanism that is disposed above the mandrel and presses and fixes onto the back bar in a state where both ends of the workpiece are butted, and a TIG welding apparatus that is disposed above the mandrel and butt welds the butt portion of the workpiece. The both ends of the work supported by the mandrel are butt-fixed on the back bar by a clamp mechanism, and this butt portion is a TIG welding device It is obtained so as to bond more butt welded to.

  This automatic welding apparatus, when pressing and fixing on the back bar of the mandrel with both ends of the workpiece being abutted, positions one end surface of the workpiece by the sensor positioning mechanism and then the other end of the workpiece on the other end surface of the workpiece. Since the end surfaces of the workpieces are abutted with each other, the butt portion of the workpiece is parallel to the axis of the mandrel, and the butt welding of the workpiece can be performed accurately.

  However, in the automatic welding apparatus, when both ends of the workpiece are brought into contact with each other, both ends of the workpiece may be displaced in the axial direction of the mandrel, and both ends of the workpiece may become uneven. In this state, butt welding is performed. In such a case, the quality of the workpiece (product) is significantly lowered. In addition, when both ends of the work are brought into contact with each other, there is a problem that skill and time are required because the workers are aligned by hand so that both ends of the work are not shifted in the axial direction of the mandrel. .

  By the way, in butt welding of thin metal plate workpieces, the arc tends to become unstable at the start of welding, and the start end of the workpiece joints may be melted down, or the tungsten electrode rods may be heavily consumed. The problem of becoming. Further, there is a problem that the output control becomes unstable even at the end of welding, and the end portion of the joint portion of the workpiece is likely to be melted down.

  In order to solve this problem, in butt welding of thin metal plate workpieces, tab materials are arranged at both ends of the butt portion of the workpiece, and the welding torch faces one of the tab materials. An arc is generated between the material and the tungsten electrode rod, and after the initial arc has stabilized, the welding torch is moved along the butt portion of the workpiece, and then energization is performed on the other tab material. It has been done to stop. If it does in this way, the butt | weld part of a workpiece | work can be butt-welded in the stable arc state, and butt-welding without defects, such as a burnout, can be performed.

Therefore, even in the conventional automatic welding apparatus described above, a tab material that protrudes upward from the upper surface of the back bar is provided in the vicinity of both ends of the back bar of the mandrel, and the one of the tab material and the tungsten electrode rod is provided. In the meantime, an initial arc is generated and the energization is stopped on the other tab material.
In this automatic welding device (automatic welding device in which a tab material is provided on a mandrel), both ends of the workpiece are pressed by pressing the end side end of the workpiece against the tab material protruding upward from the upper surface of the back bar. It is possible to prevent the mandrel from shifting in the axial direction.

However, in the automatic welding apparatus, when the clamp mechanism is pressed and fixed onto the back bar of the mandrel with both ends of the workpiece butted, the clamp mechanism simultaneously aligns the position near the butted portion of the workpiece and the tab material. Since the pressure is fixed to the mandrel side, the height of the tab material provided on the mandrel must be set equal to the thickness of the workpiece. As a result, when the workpiece is extremely thin, the height of the tab material is also considerably reduced, which makes it difficult to press the end of the workpiece against the tab material, making it difficult to set the workpiece. Yes.
In addition, when the tab material is disposed only on one side of the back bar, when both ends of the work are brought into contact with each other, both ends of the work are displaced in the axial direction of the mandrel, and both ends of the work become uneven. There was also a fear.
JP 2003-205369 A

  The present invention has been made in view of such problems, and the object thereof is to accurately match the both ends of the workpiece on the back bar of the mandrel without shifting in the axial direction of the mandrel. An object of the present invention is to provide a horizontal automatic welding apparatus.

In order to achieve the above object, the invention of claim 1 of the present invention is such that a workpiece made of a metal plate material is supported by a horizontal mandrel supported by a frame body, and both ends of the workpiece are butted against each other by a clamping mechanism. In a horizontal type automatic welding device that is pressed and fixed onto a back bar provided on the upper surface side of the mandrel and the butt portion is butt welded by a welding device, both ends of the work are in the axial direction of the mandrel. A workpiece side end positioning mechanism is provided for positioning both side ends of the workpiece so that they are abutted on the back bar without slipping, and the workpiece side end positioning mechanism is arranged at a position near one end of the back bar. On the upper surface side of the work piece, and is disposed so as to be movable up and down, protruding upward from the upper surface of the work on the back bar, and contacting one end of both ends of the work. The stopper tab is located near the other end of the back bar and can be moved up and down on the upper side of the mandrel and movable in the axial direction of the mandrel, and projects upward from the upper surface of the work on the back bar. A slide tab serving as a welding start point at which the other end of both ends of the workpiece abuts, an elastic body that urges the stopper tab and the slide tab to protrude upward from the upper surface of the workpiece on the back bar, and a slide tab Between the stopper tab and the slide tab urged to the stopper tab side by the elastic body, and holds both ends of the workpiece from both sides. When the end is pressed and fixed onto the back bar by the clamp mechanism, the stopper tab and slide tab are pushed into the mandrel by the clamp mechanism, Particular Toppatabu and the upper surface of the slide tab is configured to flush with the upper surface of the workpiece is characterized.

  In the horizontal type automatic welding apparatus according to the first aspect of the present invention, since the work side end positioning mechanism for positioning the both ends of the end of the work is provided on the mandrel, both ends of the work are not displaced in the axial direction of the mandrel. , You can always match exactly on the back bar. As a result, it is possible to perform damped butt welding satisfactorily and reliably, and to improve the quality of the butt welded workpiece itself. In addition, the operator does not need skill to align both ends of the workpiece end, and both ends of the workpiece can be abutted in a short time, thus greatly increasing the speed.

In the horizontal automatic welding apparatus according to the first aspect of the present invention, a stopper tab and a slide tab projecting upward from the upper surface of the work on the back bar are arranged at positions near both ends of the back bar of the mandrel so as to be movable up and down. When the workpiece end is pressed and fixed onto the back bar by the clamp mechanism, the stopper tab and slide tab are pushed into the mandrel by the clamp mechanism, and the upper surface of the stopper tab and slide tab is flush with the upper surface of the workpiece. Therefore, unlike the conventional automatic welding equipment, the height of the tab material does not have to be the same as the thickness of the workpiece, and the height of the stopper tab and slide tab is much higher than the thickness of the workpiece. can do. As a result, even a thin workpiece can be easily pressed against the slide tab or stopper tab, and the workpiece can be set very easily.
Furthermore, in the horizontal type automatic welding apparatus according to claim 1 of the present invention , the slide tab is disposed so as to be movable in the axial direction of the mandrel, and the slide tab is urged toward the stopper tab by an elastic body. When the end portion of the workpiece is set between the stopper tab and the slide tab, the end portion of the workpiece is held by the stopper tab and the slide tab, and positioning of the both end portions of the workpiece can be performed more reliably.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 show a horizontal automatic welding apparatus according to an embodiment of the present invention. The horizontal automatic welding apparatus is made of stainless steel, iron, zinc, or the like bent into a cylindrical shape, a tapered shape, or a rectangular tube shape. Various products such as drums, round pipes, tapered pipes, square pipes, etc. are produced by joining both ends of a workpiece W made of a metal plate such as a plated steel plate or galvanized steel plate by butt welding. The butt welding can be accurately performed without shifting in the direction.

  That is, as shown in FIGS. 1 and 2, the horizontal automatic welding apparatus has a box-shaped frame main body 1 and a horizontally long long shape that is supported by the frame main body 1 in a cantilevered state and supports a workpiece W. The mandrel 2, a long back bar 3 detachably provided on the upper surface side of the mandrel 2, and an end surface of the work W provided on the mandrel 2 so that both ends of the work W are abutted on the back bar 3 Positioning of both ends of the workpiece W so that the both ends of the workpiece W are abutted on the back bar 3 without being shifted in the axial direction of the mandrel 2. The workpiece clamping mechanism 5 is an air clamp type clamping device that is disposed above the mandrel 2 and that presses and fixes both ends of the workpiece W onto the back bar 3 in a butted state. 6 and a TIG welding device 7 which is disposed above the mandrel 2 and butt welds the butt portion of the work W. The both ends of the work W supported by the mandrel 2 are connected to the center positioning mechanism 4 and the work. The both ends are positioned and butted together, and the butted portion is pressed and fixed on the back bar 3 by the clamp mechanism 6, and the butted portion of the workpiece W is butt welded by the TIG welding device 7 in this state. Is.

As shown in FIGS. 1 and 2, the frame body 1 has a long upper frame 1a that protrudes forward in a horizontal posture at the top, and protrudes in a horizontal posture forward at the bottom and is installed on the floor surface. A base 1b is provided, and a power source device for welding, a gas cylinder for welding such as argon gas, and a compressed air source such as a compressor (both not shown) are accommodated in the frame body 1 respectively.
On the upper surface of the upper frame 1a, an operation panel 8 for setting welding conditions, electrode positions and the like at the tip portion
Is mounted on the side surface of the distal end of the upper frame 1a, and an air switch 10 for the clamp mechanism 6 is provided.
Further, a support device (not shown) composed of a support roller or the like that supports the lower surface side of the workpiece W when the both ends of the workpiece W having a large diameter are butt welded at a portion protruding forward from the frame body 1 of the base 1b. The height is freely adjustable.

As shown in FIGS. 1, 2 and 9, the mandrel 2 includes a mandrel body 2 'formed of a metal material such as an aluminum alloy into a rectangular column shape having a substantially rectangular cross section, and a base end of the mandrel body 2'. It is supported by the frame main body 1 in a cantilever state and in a horizontal posture by inserting the holding shaft 2 ″ into a mandrel guide 11 attached to the frame main body 1.
On the upper surface of the mandrel main body 2 ', a back bar mounting groove 2a in which a long back bar 3 is detachably fitted, and a workpiece both side end positioning mechanism 5 are formed at both ends of the back bar mounting groove 2a. The stopper tab 19, the slide tab 20, etc. are formed in a straight line along the longitudinal direction of the mandrel 2 in a state where the tab storage groove 2 b into which the stopper tab 19 and the slide tab 20 are fitted so as to be movable up and down is communicated.
A narrow gas groove 2c through which a shielding gas such as argon gas flows is formed along the longitudinal direction of the mandrel 2 on the bottom surface of the back bar mounting groove 2a of the mandrel body 2 ', and the center positioning mechanism 4 Recesses 2d into which a support base 18a with a piston 18b that supports the center plate 17 is fitted up and down are formed at regular intervals.
Further, on both side surfaces of the mandrel body 2 ′, bolt holes 2 e through which bolts 12 for fixing the back bar 3 fitted in the back bar mounting groove 2 a to the mandrel 2 side are inserted are fixed in the longitudinal direction of the mandrel 2. In addition to being formed at intervals, a gas supply port 2f for supplying a shielding gas such as argon gas is formed on one side surface of the mandrel 2 at regular intervals so as to communicate with the respective recesses 2d. Yes.

Further, as shown in FIGS. 1 and 2, a support shaft 14 is attached to the mandrel body 2 'so as to be removably inserted into a mandrel receiver 13 provided at the tip of the upper frame 1a.
The mandrel receiver 13 is configured to rotate 90 degrees forward and backward from a horizontal position to a vertical position by a rotary actuator 15, and is formed on the mandrel receiver 13 by rotating the mandrel receiver 13 from the horizontal position to the vertical position. By inserting the support shaft 14 provided at the tip of the mandrel body 2 'into the support hole, the tip of the mandrel body 2' can be supported.
Further, a rigid nylon inlet guide 16 formed with a downwardly inclined surface on the upper surface of the mandrel main body 2 'so that the workpiece W can be easily inserted into the mandrel 2 is attached by a bolt 12.

As shown in FIGS. 4, 7 and 10, the back bar 3 is formed of a copper material in the shape of a long rectangular column having a rectangular cross section, and is detachable from the back bar mounting groove 2a of the mandrel body 2 ′. It is inserted in. The back bar 3 absorbs excess heat when the end faces of the workpieces W are butt-welded to prevent the beads from being melted or perforated, the workpiece W being thermally distorted, and the back surface of the butt portion of the workpiece W. A shield gas is allowed to flow to the side to prevent oxidation of the weld.
Specifically, the back bar 3 is divided into left and right parts along the longitudinal direction, and the center plate 17 is inserted between the divided left and right back bars 3 'and 3' in a loosely fitted state, and argon gas is added. A slit-like groove 3a through which a shielding gas such as a gas flows is formed.
The divided left and right back bars 3 ', 3' are formed with female screw holes 3b that match the bolt holes 2e of the mandrel body 2 'at regular intervals along the longitudinal direction.

Thus, as shown in FIGS. 4 and 7, the back bar 3 is fitted into the back bar mounting groove 2a of the mandrel main body 2 ′ with the divided left and right back bars 3 ′ and 3 ′ facing each other. The left and right back bars 3 ′, 3 ′ are fastened and fixed to the mandrel 2 side with a plurality of bolts 12, so that they are attached to the mandrel 2 in a posture along the axial direction. At this time, a slit-like groove 3a is formed between the left and right back bars 3 'and 3'.
The left and right back bars 3 'and 3' have a thickness of 1 mm between the left and right back bars 3 'and 3' when the back bar 3 is mounted in the back bar mounting groove 2a of the mandrel body 2 '. The slit-like groove 3a is set to be formed. Further, the height of the left and right back bars 3 'and 3' is such that when the back bar 3 is mounted in the back bar mounting groove 2a of the mandrel main body 2 ', the flat upper surface of the back bar 3 is that of the mandrel main body 2'. It is set to protrude 1 mm above the upper surface.

  The center positioning mechanism 4 positions the end face of the workpiece W so that both ends of the workpiece W are abutted on the slit-like groove 3a of the back bar 3, and are shown in FIGS. As described above, a long center plate 17 made of a thin steel plate inserted into the slit-like groove 3a of the back bar 3 so as to freely move up and down, and a piston structure drive provided on the mandrel 2 to move the center plate 17 up and down. Part 18.

  That is, the center plate 17 is inserted in the slit-like groove 3a of the back bar 3 so as to freely move up and down. The end surface of the workpiece W is in contact with the side surface of the upper end portion protruding from the upper surface of the back bar 3. The center plate 17 is set to have a thickness of 0.5 mm. Therefore, when the center plate 17 is inserted into the groove 3a of the back bar 3, a slit-like gap through which a shielding gas such as argon gas flows is formed between the side surface of the center plate 17 and the back bar 3 '. .

  On the other hand, the drive unit 18 is fitted in each recess 2d of the mandrel 2 so as to be movable in the vertical direction, and is provided on a plurality of support bases 18a on which the center plate 17 is supported and fixed by the bolts 12, and on the lower surface of each support base 18a. The piston 18b inserted in the piston hole 2g formed in the bottom surface of the recess 2d of the mandrel 2 through the O-ring 18c so as to be slidable in the vertical direction is interposed between the back bar 3 and the support base 18a. The support base 18a and the piston 18b are urged downward, and are composed of a return compression spring 18d for positioning the upper end portion of the center plate 17 in the groove 3c of the back bar 3, and compressed from a compressed air supply source. When air is supplied from the air supply port 2h formed in the mandrel 2 to the piston hole 2g, the piston 18b, the support base 18a, and the center plate 17 are When the compression spring 18d rises against the elastic force of the compression spring 18d, the upper end of the center plate 17 projects upward from the upper surface of the back bar 3, and when the supply of compressed air is stopped, the support base 18a is supported by the elastic force of the compression spring 18d. The piston 18b and the center plate 17 are lowered, and the upper end portion of the center plate 17 is accommodated in the slit-like groove 3a of the back bar 3.

  The workpiece side end positioning mechanism 5 is provided in the vicinity of both ends of the back bar 3 of the mandrel 2, so that both ends of the workpiece W are not displaced in the axial direction of the mandrel 2, and the slit-like groove of the back bar 3. The both ends of the workpiece W are positioned so as to be abutted on 3a.

  That is, the workpiece side end positioning mechanism 5 is disposed on the upper surface side of the mandrel 2 at a position near one end of the back bar 3 so as to be movable up and down as shown in FIGS. A stopper tab 19 with which the end abuts and a position near the other end of the back bar 3 are arranged on the upper surface of the mandrel 2 so as to be vertically movable and movable in the axial direction of the mandrel 2. The slide tab 20 with which the end abuts, the elastic member 21 that urges the stopper tab 19 and the slide tab 20 to protrude upward from the upper surface of the workpiece W on the back bar 3, and the slide tab 20 toward the stopper tab 19 side. When the end of the workpiece W is pressed and fixed onto the back bar 3 by the clamp mechanism 6, the stopper tab 19 and the slide tab 20 are clamped by the clamp mechanism 6. Against the biasing force of the elastic body 21 is pushed into the mandrel 2, the upper surface of the stopper tab 19 and the slide tab 20 is configured to flush with the upper surface of the workpiece W by.

Specifically, as shown in FIG. 6, the workpiece side end positioning mechanism 5 is slidably fitted in the tab storage grooves 2b on the distal end side and the base end side of the mandrel main body 2 'so as to be slidable in the vertical direction. A front end side block member 23 and a base end side block member 24 made of aluminum alloy, and are attached to the bottom surfaces of both block members 23, 24 in a vertical posture, and a bush 25 is formed in a through hole 2i formed in the bottom surface of each tab storage groove 2b. A shaft-like stopper member 26 that is inserted and supported so as to be slidable in the vertical direction through the upper and lower sides and prevents the block members 23 and 24 from coming out of the tab housing groove 2b and restricts the upper limit positions of the block members 23 and 24. A thick plate-like stopper tab 19 made of a copper material fixed to the notch 23a formed on the upper surface of the front end side block member 23 by a bolt 12 and in contact with one side end of both ends of the workpiece W; End block A thick plate made of copper material that is supported by a notch 24a formed on the upper surface of the material 24 so as to be movable in the axial direction of the mandrel 2 via a guide rail 27 and that the other side ends of both ends of the workpiece W come into contact with. The slide tab 20 is interposed between the block members 23, 24 and the bottom surface of the tab storage groove 2b, and the block members 23, 24 are urged upward to back the stopper tab 19 and the slide tab 20. An elastic body 21 made of a compression spring that protrudes upward from the upper surface of the workpiece W on the bar 3 is interposed between the base end side block member 24 and the slide tab 20, and the slide tab 20 is connected to the distal end portion of the mandrel 2. And an elastic body 22 made of a compression spring that is urged toward the stopper tab 19, and the both ends of the workpiece W are sandwiched between the stopper tab 19 and the slide tab 20 from both sides. At the same time, when the end portion of the workpiece W is pressed and fixed onto the back bar 3 by the clamp mechanism 6, the stopper tab 19, the slide tab 20, and both block members 23 and 24 are applied to the urging force of the elastic body 21 by the clamp mechanism 6. The upper surface of the stopper tab 19 and the slide tab 20 is flush with the upper surface of the workpiece W by being pushed into the tab storage groove 2 b of the mandrel 2.
The amount of upward protrusion of the stopper tab 19 and the slide tab 20 is set so as to protrude upward by about 5 mm from the upper surface of the back bar 3. The amount of movement of the slide tab 20 in the axial direction of the mandrel 2 is set to about 5 mm.

The clamp mechanism 6 presses and fixes the work W supported by the mandrel 2 on the back bar 3 in a state where both ends of the work W are in contact with each other. As shown in FIG. The left and right support plates 29 are supported so as to be swingable in the vertical direction via the upper and lower sides of the mandrel 2, and the work supported by the mandrel 2 is attached to the front ends of both support plates 29. Supplied between the left and right clamps 30 made of copper, which are in contact with the upper surfaces of both end portions of W and the upper surfaces of the stopper tab 19 and the slide tab 20, and the upper frame 1 a and the left and right support plates 29. The air tube 31 that expands and pushes the left and right support plates 29 and the left and right clamps 30 downward, and the pull that biases the left and right support plates 29 and the left and right clamps 30 upward. Ri and spring 32, and a adjusting screw 33 or the like for adjusting the gap between the left and right support plates 29 and the left and right left and right clamp 30 the clamp 30 by horizontal movement of.
The length of the left and right clamps 30 is such that the end of the workpiece W supported by the mandrel 2 can be pressed and fixed onto the back bar 3 over the entire width direction, and the stopper tab 19 and the slide tab 20 can be fixed. Both block members 23 and 24 are set so as to be pushed into the tab storage groove 2b. This clamp 30 is mainly for interrupting the spread of the arc and intensively applying the arc energy to the butt portion of the workpiece W.

  Thus, according to the clamp mechanism 6, when the compressed air is supplied from the compressed air source to the air tube 31 to expand the air tube 31, the left and right support plates 29 and the left and right clamps 30 are elastic of the tension spring 32. The left and right clamps 30 abut against both ends of the work W supported by the mandrel 2 to press and fix the both ends of the work W on the back bar 3 and the left and right clamps. 30 pushes the stopper tab 19, slide tab 20, and both block members 23, 24 into the tab storage groove 2 b of the mandrel 2 against the elastic force of the elastic body 21, and the upper surface of the stopper tab 19 and slide tab 20 is moved to the workpiece W. To be flush with the top surface. When the supply of compressed air is stopped, the left and right support plates 29 and the left and right clamps 30 are swung upward by the elastic force of the tension spring 32, and the pressed state of the workpiece W is released, and the stopper tab 19 and slide The tab 20 and both block members 23 and 24 are raised by the elastic force of the elastic body 21 to return to the original position.

  As shown in FIG. 1, the TIG welding device 7 includes a traveling table 35 disposed on the upper surface of the upper frame 1 a via a guide rail 34 so as to be reciprocally movable in the longitudinal direction of the mandrel 2, and is movable up and down to the traveling table 35. A torch vertical motion drive device (illustrated) comprising a welding torch 36 with a tungsten electrode rod inserted and a servo motor for moving the welding torch 36 up and down while flowing a shielding gas such as argon gas from the tip. Monitoring camera (not shown) to check the welding status (consumption of the tungsten electrode rod, arc condition, etc.) and the butt end of the workpiece W, and the tungsten electrode rod and workpiece before starting welding An electrode contact detection device (not shown) that makes it easy to set the gap of W and immediately detects a contact accident between the tungsten electrode rod and the workpiece W during welding, and a traveling table 35 A driving device (not shown) comprising a motor that reciprocates in the longitudinal direction of the mandrel 2 and a ball screw mechanism, etc., is provided, and when the butt portion of the workpiece W is welded, the tip of the welding torch 36 is automatically raised. The traveling table 35 and the welding torch 36 supported by the carriage 35 are linearly moved along the butt portion of the workpiece W at a predetermined speed.

  Next, a case where the end faces of the workpiece W bent into a cylindrical shape, a tapered shape, or each cylindrical shape are butt welded using the horizontal automatic welding apparatus described above will be described.

  In addition, the workpiece W was bent into a cylindrical shape, a tapered shape, or each cylindrical shape made of a metal plate material such as stainless steel, iron, electrogalvanized steel plate, galvanized steel plate having a thickness of about 0.2 mm to 1.2 mm. Work W is used. Welding conditions such as welding current, arc length, supply amount of shield gas, traveling speed of welding torch 36, tip shape of tungsten electrode rod, etc. are optimum conditions depending on the material, thickness, width, etc. of workpiece W. Of course, it is set below.

First, the tip of the mandrel 2 is supported by a mandrel receiver 13 to prevent the long mandrel 2 from being bent, and the center plate 17 of the center positioning mechanism 4 provided on the mandrel 2 is raised by the drive unit 18 to be centered. After the upper end portion of the plate 17 protrudes upward from the upper surface of the back bar 3 (see FIG. 11), the opening portion of the bent workpiece W is spread by hand and inserted into the mandrel 2.
In this example, the work W is inserted into the mandrel 2 after the front end of the mandrel 2 is supported by the mandrel receiver 13, but the work W is inserted into the mandrel 2 from the front end of the mandrel 2. Thereafter, the tip of the mandrel 2 may be supported by the mandrel receiver 13.

When the work W is inserted into the mandrel 2, one end of the work W is positioned between the stopper tab 19 and the slide tab 20 so as to come into contact with the upper surface of the back bar 3 and against the upper surface of the back bar 3. The end surface (tip) of the end portion of the workpiece W in contact is brought into contact with the side surface of the upper end portion of the center plate 17.
That is, the side end of one end of the work W is pressed against the end surface of the slide tab 20, and the slide tab 20 is slid to the base end side of the mandrel 2 against the urging force of the elastic body 22 by the work W. Then, one end of the work W is positioned between the stopper tab 19 and the slide tab 20, and in this state, one end of the work W is brought into contact with the upper surface of the back bar 3 and the upper surface of the back bar 3. After the end surface (tip) of the end portion of the workpiece W brought into contact with the upper end side surface of the center plate 17 is brought into contact with the workpiece W, the movement of the slide tab 20 is stopped (see FIG. 12). Then, the slide tab 20 moves to the stopper tab 19 side by the elastic force of the elastic body 22, one end portion of the work W comes into contact with the upper surface of the back bar 3, and its end surface (front end) is the side surface of the upper end portion of the center plate 17. Is held between the stopper tab 19 and the slide tab 20 (see FIG. 13).
At this time, the slide tab 20 and the stopper tab 19 protrude upward from the upper surface of the back bar 3 and protrude upward from the upper surface of the work W set on the back bar 3. However, it is very easy to set the workpiece W on the back bar 3.

  When one end of the workpiece W is set on the back bar 3 of the mandrel 2, one clamp 30 of the clamp mechanism 6 (the clamp 30 positioned above the end of the workpiece W in contact with the side surface of the center plate 17). ) Is lowered, and one end of the workpiece W is pressed and fixed onto the back bar 3 by the clamp 30 (see FIGS. 14 and 15). At this time, the clamp 30 pushes the stopper tab 19, the slide tab 20, and the both block members 23, 24 into the tab storage groove 2 b against the elastic force of the elastic body 21, and the upper surface of the stopper tab 19 and the slide tab 20. The upper surface is flush with the upper surface of the workpiece W.

  When one end of the workpiece W is pressed and fixed onto the back bar 3 by the clamp mechanism 6, the supply of the compressed air supplied to the drive unit 18 of the center positioning mechanism 4 is stopped, and the elasticity of the return compression spring 18d is restored. The support base 18a and the center plate 17 are lowered by force, and the upper end portion of the center plate 17 is stored in the groove 3a of the back bar 3 (see FIGS. 14 and 15). At this time, since the center plate 17 descends straightly in a vertical posture, it cannot be said that one end portion of the workpiece W contacting the side surface of the center plate 17 is caught by the descending center plate 17. As a result, even when the workpiece W is thin or the workpiece W is made of a soft metal material, deformation of the end portion of the workpiece W can be prevented.

  Thereafter, the end surface of the other end of the workpiece W is abutted against the end surface of one end of the workpiece W that is first pressed and fixed on the back bar 3 by visual observation, and the other clamp 30 of the clamp mechanism 6 is lowered. Then, the other end of the workpiece W is pressed and fixed onto the back bar 3 by the clamp 30 (see FIGS. 16 and 17). At this time, since one end of the work W is positioned in advance in the axial direction of the mandrel 2 by the stopper tab 19 and the slide tab 20 of the work both-side end positioning mechanism 5, the other end of the work W is The end of the workpiece W previously pressed and fixed to the back bar 3 can be always butted accurately without being displaced in the axial direction of the mandrel 2.

Then, when both ends of the workpiece W are butt-fixed on the back bar 3, the TIG welding apparatus 7 supplies the shield gas such as argon gas to the slit-like groove 3 a of the back bar 3 from the gas supply port 2 f. The butt portion of W is butt welded (see FIG. 17).
That is, the welding torch 36 is lowered, the tip of the tungsten electrode rod is positioned near the surface of the slide tab 20, an arc is generated between the tip of the tungsten electrode rod and the slide tab 20, and this arc is stabilized. After reaching the state, the traveling table 35 is advanced by the drive device and the welding torch 36 is caused to travel along the butt portion of the workpiece W at a predetermined speed, and then the welding torch 36 comes onto the stopper tab 19. Stop the current at the point and stop the arc. Thus, if the slide tab 20 is a welding start point and the stopper tab 19 is a welding end point, the butt portion of the workpiece W is welded in a stable arc state, and butt welding without defects such as burn-out can be performed.

  When the butt welding of the workpiece W is completed, the supply of the shielding gas to the back bar 3 is stopped, and the welding torch 36 of the TIG welding apparatus 7 returns to the original position. Thereafter, the pressing and fixing state of the work W by the clamp mechanism 6 is released, the mandrel receiver 13 is rotated from the vertical position to the horizontal position, the tip of the mandrel 2 is opened, and the work W is pulled out from the mandrel 2. In this manner, a drum, a round pipe, a tapered pipe, or a square pipe is produced from the workpiece W bent into a cylindrical shape, a tapered shape, or each cylindrical shape.

Since the horizontal automatic welding apparatus described above is provided with the workpiece both-side end positioning mechanism 5 for positioning the both ends of the end portion of the workpiece W on the mandrel 2, the both ends of the workpiece W are not displaced in the axial direction of the mandrel 2. , It is always possible to match the back bar 3 accurately. As a result, the butt welding of the workpiece W can be performed well and reliably, and the quality of the workpiece W itself which has been butt welded can be improved. However, the operator does not need skill to align both ends of the workpiece W. Thus, both ends of the workpiece W can be matched in a short time, and the speed can be greatly increased.
Further, this horizontal type automatic welding apparatus has a stopper tab 19 and a slide tab 20 protruding upward from the upper surface of the work W on the back bar 3 at positions near both ends of the back bar 3 of the mandrel 2 so as to be movable up and down. The stopper tab 19 and the slide tab 20 are pushed into the mandrel 2 by the clamp mechanism 6 when the clamp mechanism 6 is pressed and fixed on the back bar 3 with both ends of the workpiece W being in contact with each other. Since the upper surface of the slide tab 20 is flush with the upper surface of the workpiece W, the height of the tab material does not need to be the same as the thickness of the workpiece W as in the conventional automatic welding apparatus, and the stopper tab 19 and the slide tab 20 can be made considerably higher than the thickness of the workpiece W. As a result, even if the workpiece W is thin, the side ends thereof can be easily pressed against the slide tab 20 and the stopper tab 19, and the workpiece W can be set very easily.
Further, in this automatic welding apparatus 7, the slide tab 20 is disposed so as to be movable in the axial direction of the mandrel 2, and the slide tab 20 is urged toward the stopper tab 19 by the elastic body 22, so that the stopper tab When the end of the workpiece W is set between the slide tab 20 and the slide tab 20, the end of the workpiece W is held by the stopper tab 19 and the slide tab 20, and the positioning of the both ends of the workpiece W is further improved. It can be done more reliably.

  In the above-described embodiment, the mandrel 2 is formed in a prismatic shape. However, in other embodiments, the mandrel 2 may be formed in a columnar shape.

  In the above embodiment, the upper surface of the back bar 3 is formed in a flat shape. However, in other embodiments, the upper surface of the back bar 3 is formed in an arc shape. Also good.

  In the above embodiment, the back bar 3 is divided into left and right parts along the longitudinal direction, and the slit-like groove 3a is formed between the divided left and right back bars 3 'and 3'. In another embodiment, the back bar 3 is integrally formed without being divided into left and right parts, and a slit-like groove 3a is formed on the center line of the back bar 3 along the longitudinal direction. The center plate 17 may be inserted into 3a so as to freely move up and down in a loosely fitted state, and a shielding gas such as argon gas may be supplied.

  In the above-described embodiment, the stopper tab 19 is provided on the distal end side of the mandrel 2 and the slide tab 20 is provided on the proximal end side of the mandrel 2. However, in the other embodiments, In other words, the stopper tab 19 may be provided on the proximal end side of the mandrel 2 and the slide tab 20 may be provided on the distal end side of the mandrel 2.

  In the above embodiment, the butt welding of the workpiece W bent into a cylindrical shape, a tapered shape, or a rectangular tube shape is performed. In other embodiments, the flat plate-like workpiece W is used. Butt welding may be performed.

1 is a side view of a horizontal automatic welding apparatus according to an embodiment of the present invention. It is a front view of a horizontal type automatic welding apparatus. It is a partially omitted side view of a mandrel provided with a back bar and a workpiece both side end positioning mechanism. FIG. 6 is a partially omitted plan view of a mandrel provided with a back bar and a workpiece side end positioning mechanism. FIG. 6 is a partially omitted plan view of a mandrel provided with a center positioning mechanism and a workpiece both side end positioning mechanism. FIG. 5 is a partially omitted vertical side view of a mandrel provided with a back bar, a center positioning mechanism, and a workpiece both side end positioning mechanism. It is an enlarged vertical front view of a mandrel provided with a back bar and a center positioning mechanism. It is a vertical front view of a clamp mechanism. The mandrel is shown, (A) is a partially cutaway side view of the mandrel, and (B) is a plan view of the mandrel. It is a disassembled perspective view of a back bar, a center positioning mechanism, and a workpiece both side end positioning mechanism. It is a partially omitted vertical side view of the mandrel with the center plate raised. FIG. 4 is a partially omitted enlarged plan view of a state in which one end of the work is set on a back bar of a mandrel. It is a partially omitted enlarged plan view in a state where one end of the work is set on the back bar of the mandrel. It is an enlarged vertical front view of the state which positioned and clamped one edge part of the workpiece | work. It is a vertical side view of the state which positioned and clamped one edge part of the workpiece | work. It is a partially omitted enlarged plan view in a state where both ends of the workpiece are positioned and clamped. It is an expanded vertical front view of the state which clamped and welded the both ends of a workpiece | work.

Explanation of symbols

  1 is a frame main body, 2 is a mandrel, 3 is a back bar, 5 is a workpiece side-end positioning mechanism, 6 is a clamping mechanism, 7 is a welding device, 19 is a stopper tab, 20 is a slide tab, and W is a workpiece.

Claims (1)

A work (W) made of a metal plate is supported on a mandrel (2) in a horizontal posture supported by the frame body (1), and both ends of the work (W) are butted against each other by a clamp mechanism (6). In the horizontal type automatic welding apparatus in which the butt portion is pressed and fixed onto the back bar (3) provided on the upper surface side of the) and the butt portion is butt welded by the welding apparatus (6). In the mandrel (2), Both-side end positioning mechanism for positioning the workpiece (W) so that both ends of the workpiece (W) are abutted on the back bar (3) without shifting in the axial direction of the mandrel (2) ( 5), and the workpiece both side end positioning mechanism (5) is disposed on the upper surface side of the mandrel (2) at a position near one end of the back bar (3) so as to be movable up and down. Upper surface of upper work (W) The stopper tab (19) which is a welding end point where one end of both ends of the workpiece (W) abuts upward and the position of the mandrel (2) near the other end of the back bar (3) It is arranged on the upper surface side so as to be movable up and down and movable in the axial direction of the mandrel (2), protrudes upward from the upper surface of the work (W) on the back bar (3), and is formed at both ends of the work (W). The slide tab (20), which is the welding start point with which the other side end abuts, the stopper tab (19), and the slide tab (20) should protrude above the upper surface of the work (W) on the back bar (3). An elastic body (21) for urging and an elastic body (22) for urging the slide tab (20) toward the stopper tab (19) are provided, and the stopper is formed by the stopper tab (19) and the elastic body (22). Urged to the tab (19) side While holding both ends of the workpiece (W) from both sides with the ride tab (20), and pressing and fixing the end of the workpiece (W) onto the back bar (3) by the clamp mechanism (6), The stopper tab (19) and the slide tab (20) are pushed into the mandrel (2) by the clamp mechanism (6), and the upper surfaces of the stopper tab (19) and the slide tab (20) are flush with the upper surface of the workpiece (W). A horizontal automatic welding apparatus characterized by being configured to be

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